Peter Lieven from KAMP.de discovered a problem with TurnKey 13.0 where the OpenSSH ECDSA key is not regenerated on firstboot like the RSA and DSA host keys.

We've issued a signed hotpatch to TurnKey Core 13.0 that regenerates the ECDSA SSH host key. TurnKey deployments that have not disabled automatic security updates (it's on by default) will have their ECDSA SSH host key regenerated automatically within the next 24 hours.

Here's another example of why we need free software running the Internet. When I bought my Medialink router it was the most popular brand of wireless router on Amazon.com. It is created by a Chinese corporation called Tenda.

@pa2013 helpfully posted Alon's BitKey announcement from last week to the Bitcoin Reddit, which sparked an interesting discussion regarding whether or not you can safely trust BitKey to perform air-gapped transactions. I started responding there but my comment got so long I decided to turn it into a blog post.

In our quest to make the upcoming TurnKey 11.0 release more "turnkey", I set out to extend the firstboot inithooks to include application specific configuration hooks such as setting of the admin password, email and domain to serve (where applicable).

I'm glad to announce that the quest is now over, and that puts the end to default passwords.

Background: how a backup key works

In TKLBAM the backup key is a secret encrypted with a passphrase which is uploaded to the Hub. Decrypting the backup key yields the secret which is passed on to duplicity (and eventually to GnuPG) to be used as the symmetric key with which backup volumes are encrypted on backup and decrypted on restore.

When you create a new backup, or change the passphrase on an existing backup, a new backup key is uploaded to the Hub where it is stored in the key field for that backup record.

When you restore, tklbam downloads the backup key from the Hub and decrypts it locally on the computer performing the restore. Note that the Hub only allows you to download the backup key for backup records to which you have access (e.g., you are the owner).

Only you can decrypt your passphrase protected backups

All of this matters because it means that as long as you use a passphrase to protect the key, even the Hub can't decrypt your backups, only you can - provided you remember the passphrase (or failing that, at least have the escrow key stored in a safe place).

In other words, the decryption of the backup key happens locally and at no point does the passphrase reach the Hub, so we can't decrypt your backup even if you asked us to. Neither can an attacker that has theoretically compromised the Hub, or a government agency that comes kicking down our door with a court warrant.

The problem with cryptographic passphrases

But wait. If an attacker has local access to the key, his ability to run dictionary attacks to find the key's passphrase is limited only by the computational resources he can throw at it.